/* Copyright  2009
   @Author
   Richard Changde Yin            e-mail yinchangde@hotmail.com

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/**
 * @filename: select_send.h
 */


#ifndef __SELECT_SEND_H__
#define __SELECT_SEND_H__

class select_send :public select_result {
  /**
    True if we have sent result set metadata to the client.
    In this case the client always expects us to end the result
    set with an eof or error packet
  */
  bool is_result_set_started;

public:
  select_send() :is_result_set_started(false) {}

  bool send_eof()
  {

    ha_release_temporary_latches(session);

    /* Unlock tables before sending packet to gain some speed */
    if (session->lock)
    {
      db_unlock_tables(session, session->lock);
      session->lock= 0;
    }
    session->my_eof();
    is_result_set_started= 0;
    return false;
  }

  bool send_fields (List<Item> &list, uint32_t flags)
  {
    bool res;
    if (!(res= session->protocol->send_fields(&list, flags)))
      is_result_set_started= 1;
    return res;
  }

  void abort()
  {
    return;
  }


  /**
    Cleanup an instance of this class for re-use
    at next execution of a prepared statement/
    stored procedure statement.
  */

  virtual void cleanup()
  {
    is_result_set_started= false;
  }

  /* Send data to client. Returns 0 if ok */

  bool send_data(List<Item> &items)
  {
    if (unit->offset_limit_cnt)
    { // using limit offset,count
      unit->offset_limit_cnt--;
      return false;
    }

    /*
      We may be passing the control from mysqld to the client: release the
      InnoDB adaptive hash S-latch to avoid thread deadlocks if it was reserved
      by session
    */
    ha_release_temporary_latches(session);

    List_iterator_fast<Item> li(items);

    Protocol *protocol= session->protocol;

    char buff[MAX_FIELD_WIDTH]; // TO DO: Use configuration.

    String buffer(buff, sizeof(buff), &my_charset_bin);

    protocol->prepare_for_resend();
    Item *item;
    while ((item=li++))
    {
      if (item->send(protocol, &buffer))
      {
        protocol->free(); // Free used buffer
        my_message(ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES), MYF(0));
        break;
      }
    }
    session->sent_row_count++;

    if (session->is_error())
    {
      protocol->remove_last_row();
      return true;
    }

    if (session->client_vio_ok())
       return(protocol->write());
    return false;
  }
};

#endif /* __SELECT_SEND_H__ */
